American Champion Aircraft (ACA) 8KCAB Super Decathlon

By John Sausedo (25 September 2003)

started flying airplanes in 1989, at the tender young age of 17. My first aerobatic flight was in 1990 in an 8KCAB, otherwise known as the Super Decathlon. I rode in the back seat and in the front was my close friend who started flight training around the same time and age as I did. He went on to fly F-15's for the USAF, by the way. Anyway, during the flight we did loops, Cuban-8's, Aileron Rolls and Slow Rolls and just cruised around upside down. It was a blast and I was hooked. Since that time I went on to become a flight instructor and for a time I specialized in aerobatic training. One of the airplanes I find to be best suited for the task of introducing a pilot to aerobatics is the 8KCAB.

I won't bore you with the gory details of the history of the airplane. That can be found with a search on the Internet. But, its roots can be traced back to the Aeronca 7AC Champ. Since then, the Champ has evolved into the Citabria line of airplanes (Airbatic spelled backwards), which led to the Super D. The only real difference between the Citabria line of airplanes and the Super D is the wing. The Citabria uses a traditional, flat bottomed wing while the Super D has a symmetrical airfoil.

You may ask why when there are the super performing airplanes like the Pitts Special S-2B or Extra 300 that can be found at some flight schools. Well, having flown and instructed in airplanes like the Pitts, I find that anyone can do aerobatics in these airplanes without too much thought. That doesn't mean they will be good, but it is very easy to do loops and rolls in these airplanes. The 8KCAB is underpowered and doesn't sustain energy too well during this type of maneuvering. That fact alone makes it a good aerobatic trainer because it teaches the pilot how to manage the aircraft's energy to do something like make a loop round as opposed to a loop that looks like an lower case "L".

When I found the 8KCAB, by Dave Harbold, available for download at FlightSim.Com, I jumped on it to see if they got it right. For a freeware download, or for any download, they came pretty darn close. There are a few things that aren't quite right, but the overall effect is there. And the visuals are fantastic. Just like sitting in the real thing. With that said, let's get on with it.

Installation

Designer Dave Harbold made it easy for you. Just extract the files and run the setup file and away it goes. You have two choices, one for DXT3 or 32 bit graphics. DXT3 is for those with the slower running computers (like me). I also tried the 32 bit option and the visuals of the airplane seem to be crisper in appearance and I didn't notice a significant loss of frame rate. The loading time was a hair longer than normal, but for those with the fast machines to run Flight Sim, it will not be a problem. Once installed, you have a choice of five different paint schemes, each one holding true to the traditional paint schemes found on Decathlons.

The Cockpit

The first thing you see is a nice panel and the top of the nose of the airplane. Very nice. The pilot point of view is exceptional. The visibility is pretty close to what you would get in the real thing. The Virtual Cockpit is nice. You can look up at the wing roots and see the fuel gauge...right where it is supposed to be. They even have a placard in place with the entry speed for some of the aerobatic maneuvers, just like the real thing.

When you look down, below the cockpit, you will see in the appropriate places throttle, carb heat control, propeller control knob, and mixture control. Even further down you will notice carpet on the floorboards and the push-pull rods than connect the front rudder pedals to the rear ones. A quick glance on the left side and you will see the elevator trim knob. Very nice attention to detail.

Taxiing

Taxiing the airplane is just like taxiing any other light airplane. You use the rudder for left and right. The Super Decathlon is equipped with a steerable tailwheel connected by cables from the rear set of rudder pedals. And when you use just the rudder, the turns are just like the real thing. Where it falls short is if you are trying to do an extremely tight turn. Normally this would be achieved by applying differential braking in the direction of the turn, i.e., you want a tight turn to the right; you would apply right rudder and some right brake. This will allow the tailwheel to essentially become a free castoring tailwheel allowing the airplane to turn on a dime. This doesn't happen in the Flight Sim version. Oh well, just plan accordingly and you will not have a problem.

Takeoff and Climb

After lining up on runway 25R at Livermore Municipal Airport (KLVK), I applied full throttle and glanced at the engine instruments. 27" of manifold pressure (MP) and 2700 RPM...right where they should be. A brief takeoff roll, rotate at about 60-65 Knots Indicated Airspeed (KIAS) and we are airborne. Place the nose slightly above the horizon, pull the power back to 25" of MP and 2500 RPM and the airspeed will settle to roughly 70 KIAS and a climb rate of about 800 Feet Per Minute. Not bad...this is with full fuel which I used to simulate two people and about half fuel. This is a typical profile when I would instruct in the airplane. A straight out departure to head towards San Francisco and we are on our way. I've always wanted to loop a Super D over the city. Turns, both left and right, are correctly simulated. Not too much nose drop, but enough to where you need just a hint of back pressure on the stick to keep it from lowering. The visuals during this are fantastic. I put the nose right where it is supposed to be, based on visual reference with the nose in relation to the horizon, and the airplane flies true to form.

Cruise

During cruise flight at an altitude of 4500 feet and the power set at about 22" of MP and the prop turning at 2500 RPM yielded a cruise speed of close to 120 kts. That's about 138 mph. Pretty close to the book number, but a little on the slow side. But you know what? In my 14 or so years of flying I don't think I have ever flown a light airplane that met book numbers, even new ones. Another point is the placement of the nose during cruise. In a word, excellent. I told my students to place the horizon line about halfway up the windscreen. You do that, and you will be very close to level flight at normal cruise speed. Visibility is just as it is in the real thing, excellent. I look to the left or right and it really reminds me of being in the real thing.

Aerobatics

Down to the nitty gritty. Aerobatics in the real Super D are a joy. The same applies here. For a simple aileron roll, lower the nose to 105 KIAS, pull the nose up to 30 degrees and put the stick to the left or right and hang on! It should be a 1-G roll and the nose will end up about 10-20 degrees below the horizon when done. This is modeled very well. The only complaint is the roll rate of the airplane is a bit on the fast side. I just don't throw the stick all the way over and I can get the roll rate to come down to what the real airplane does. In the real airplane, it should take close to 3 seconds to do a complete roll. Slow rolls, increase speed by about 10 knots, put the nose to the horizon (if it isn't already there) and start rolling. When inverted, add just a little forward pressure on the stick to keep the nose from going below the horizon...just remember to gradually release the forward pressure when coming out of the inverted position otherwise you will force the nose down way below the horizon.

Loops I like. Both real and simulated. This Super-D loops like the real thing. Down to 120 KIAS and pull back on the stick and up and over it goes.

Other maneuvers like the Cuban-8, Reverse Cuban-8, Barrel Roll, Split-S, and Immelman can be done as well and are a joy to fly. Hammerheads (or Stall Turn) can be done as well, just start adding rudder at about 50 and it should work out OK.

Inverted flying is also easy. Just put the nose of the airplane above the horizon line and hold it. You might have to tweak it a little to maintain level flight. I just put the nose where I do in the real thing and what do you know? The airplane maintained altitude.

Landing

Landing the Super D is a joy. One of the easiest tailwheel airplanes to land, both in real life and in flight sim. Wheel landings are the easiest. Just approach at about 70 KIAS and touch the mains down on to the runway and let it decelerate. Don't be too early to bring the tail down, or you will be airborne. Not a good place to be when you are trying to land! Three-point landings, or full stall landings, are a little trickier, but can be done with a bit of practice. Just like the real thing!

Major Gripes

OK, now for some of the negative stuff. The only glaring issue I have with this airplane are the stall characteristics. But, with the lack of good stall characteristics it leads to problems with two other maneuvers. The spin and the snap roll. I'll get to that in a second.

When you do a power off stall in the Super D in real life, you just release the back pressure on the stick, apply full throttle and it will recover with a minimal loss of altitude. Maybe 100-150 feet. In the sim version, when you stall you have to force the nose WAY down below the horizon, add power and wait, usually with a loss of about 700 feet. It seems to take forever to accelerate to an acceptable speed to bring the nose back up. If you try to raise the nose a little early, the airplane remains in a stalled condition and recovery is impossible.

This leads to problems with the spin and snap roll. The airplane just doesn't want to spin. It gets about half-way through a rotation and then just pretty much stops with the nose down, falling out of the sky. The same thing happens when I try to snap roll the airplane. I enter at about 100-110 KIAS, pull the stick all the way back, throw rudder in the direction I want to snap roll, and the airplane just stops about half-way through and does the fall-O-doom again.

Overall, the airplane is a very nice addition to the MS fleet. It does fly nice, it makes a good sightseeing vehicle and a fun aerobatic platform. It is also a very good looking airplane. The attention to detail is superlative. Just stay away from stalls and you will be good to go!

John Sausedo
GoVerticl@aol.com

Download the 8KCAB Super Decathlon

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